The horse are naturally like this I think the french equivalent is percheron, strong labor horses.

Scientifics have noticed, that animal presenting mutation because of radiation, do not breed… therefore, there is no new mutant race overlord or whatesoever. There is just a lot of overtime for Darwin. Meanwhile those that survive and breed must be some really tought mofo…

Did the helicopter hit a giant horse’s head and crash into the reactor spilling radiation out and killing the pilot before he actually hit the ground at high speed. or maybe the guy in the foreground of the helicopter shot is the pilot and the helicopter crashed cos the pilot was on the ground flying it via radiation control.